Languages and People Bridged Across Bering Sea for Millennia

A new study on the relationships between ancient languages corroborates the hypothesis that the first Native Americans spent thousands of years living along a vast swath of now sunken land bridging the Asian and North American continents.

North America's first inhabitants migrated from mainland Asia across a land bridge spanning the Bering Sea before traveling south and eventually settling across the land. But for several years now, geneticists and archaeologists have been theorizing that the migration was not as simple as crossing the land bridge and never looking back, but that the first Native Americans inhabited the expansive land bridge known as Beringia for as many as 10,000 years and that a back-and-forth migration may have taken place. 

Known as the Beringian standstill hypothesis, the idea has gained traction over the years. Last month a team of researchers offered theories on the habitation of Beringia, and now, in a study published in the journal PLOS One, a team of linguists explore the relationship between North American and Central Siberian languages and their connection to ancient migrating people. 

The researchers, Mark Sicoli, from Georgetown University and Gary Holton from University of Alaska Fairbanks, suggest that language can be used to understand the migration patterns of ancient people.

Sicoli and Holton focused on a proposed language family known as the Dené-Yeniseian. This family, which combines languages of two geographically distant groups, suggests that there are common language elements between the North American Na-Dene languages and the Yeniseian languages of Central Siberia.

The team used a tactic typically reserved for evolutionary biologists called phylogenetic analysis, where a tree is constructed to represent relationships of common ancestry based on shared traits.

The researchers used what they call linguistic phylogeny to work out how 40 languages diffuses across Asia and North America. To do this, they coded a linguistic data set from all the languages, modeled a relationship between the data, and then modeled that data against migration patterns from Asia into North America, or out of Beringia.

The analysis revealed a back-and-forth linguistic migration, with Na-Dene languages following along the North American coast, but also a backward migration of Yeniseian languages, followed by a later dispersal of North American interior Na-Dene languages.

"We used computational phylogenetic methods to impose constraints on possible family tree relationships modeling both an Out-of-Beringia hypothesis and an Out-of-Asia hypothesis and tested these against the linguistic data," Sicoli said in a statement. "We found substantial support for the out-of-Beringia dispersal adding to a growing body of evidence for an ancestral population in Beringia before the land bridge was inundated by rising sea levels at the end of the last ice age."

Although, just like other theories based on the Beringian standstill hypothesis, the linguists cannot conclusively prove their ideas, it does suggest that the migration of people from Asia to the North American might not have happened as a one-way trip.